> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rampartlabs.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Uniswap V4

> V4 Hooks AMM - custom pool logic via hooks on Monad Mainnet

<Info>
  **TVL:** \~\$2M | **Type:** V4 Hooks AMM | **Docs:** [docs.uniswap.org/contracts/v4](https://docs.uniswap.org/contracts/v4)
</Info>

## Overview

Uniswap V4 introduces a singleton `PoolManager` architecture and a hooks system, allowing custom logic to execute at key lifecycle points (before/after swap, before/after LP operations). All pools are managed by a single contract, reducing gas costs via EIP-1153 transient storage.

Pools are identified by a `V4PoolKey` struct instead of a simple address.

## Types

### V4PoolKey

```typescript theme={null}
type V4PoolKey = {
  currency0: Address    // lower address token
  currency1: Address    // higher address token
  fee: number           // fee tier in bps (e.g. 3000)
  tickSpacing: number   // tick spacing (e.g. 60)
  hooks: Address        // hooks contract (0x0 for no hooks)
}
```

<Note>
  `currency0` must always be the lexicographically lower address. The SDK handles sorting automatically in all helper functions.
</Note>

## Functions

### getUniswapV4Pools()

Returns all initialized Uniswap V4 pools on Monad.

**Returns**

| Field          | Type        | Description               |
| -------------- | ----------- | ------------------------- |
| `poolId`       | `Hex`       | 32-byte pool identifier   |
| `poolKey`      | `V4PoolKey` | Full pool key struct      |
| `sqrtPriceX96` | `bigint`    | Current sqrt price Q64.96 |
| `tick`         | `number`    | Current tick              |
| `liquidity`    | `bigint`    | Active liquidity          |

```typescript theme={null}
import { getUniswapV4Pools } from 'rampart-monad'

const pools = await getUniswapV4Pools()
console.log(`${pools.length} V4 pools found`)
console.log(pools[0].poolKey.hooks) // hooks contract
```

***

### getUniswapV4PoolState()

Reads the full state of a specific V4 pool by its pool key.

**Parameters**

| Name      | Type        | Description            |
| --------- | ----------- | ---------------------- |
| `poolKey` | `V4PoolKey` | Pool identifier struct |

**Returns**

| Field          | Type     | Description        |
| -------------- | -------- | ------------------ |
| `sqrtPriceX96` | `bigint` | Current sqrt price |
| `tick`         | `number` | Current tick       |
| `protocolFee`  | `number` | Protocol fee       |
| `lpFee`        | `number` | LP fee             |

```typescript theme={null}
import { getUniswapV4PoolState } from 'rampart-monad'

const state = await getUniswapV4PoolState({
  currency0: '0x0000000000000000000000000000000000000000',
  currency1: '0x...', // USDC
  fee: 3000,
  tickSpacing: 60,
  hooks: '0x0000000000000000000000000000000000000000'
})
console.log(`Current tick: ${state.tick}`)
```

***

### getUniswapV4Price()

Returns the spot price for a pool key.

**Parameters**

| Name      | Type        | Description            |
| --------- | ----------- | ---------------------- |
| `poolKey` | `V4PoolKey` | Pool identifier struct |

**Returns** `number`. price of `currency0` denominated in `currency1`.

```typescript theme={null}
import { getUniswapV4Price } from 'rampart-monad'

const price = await getUniswapV4Price({
  currency0: '0x0000000000000000000000000000000000000000',
  currency1: '0x...', // USDC
  fee: 3000,
  tickSpacing: 60,
  hooks: '0x0000000000000000000000000000000000000000'
})
console.log(`Price: ${price}`)
```

***

### simulateUniswapV4Swap()

Simulates a V4 swap without executing a transaction.

**Parameters**

| Name         | Type        | Description                         |
| ------------ | ----------- | ----------------------------------- |
| `poolKey`    | `V4PoolKey` | Target pool                         |
| `amountIn`   | `bigint`    | Exact input amount                  |
| `zeroForOne` | `boolean`   | `true` = swap currency0 → currency1 |

**Returns**

| Field               | Type     | Description             |
| ------------------- | -------- | ----------------------- |
| `amountOut`         | `bigint` | Expected output         |
| `priceImpact`       | `number` | Percentage price impact |
| `sqrtPriceLimitX96` | `bigint` | Sqrt price after swap   |

```typescript theme={null}
import { simulateUniswapV4Swap } from 'rampart-monad'

const sim = await simulateUniswapV4Swap(
  {
    currency0: '0x0000000000000000000000000000000000000000',
    currency1: '0x...', // USDC
    fee: 3000,
    tickSpacing: 60,
    hooks: '0x0000000000000000000000000000000000000000'
  },
  1_000_000_000_000_000_000n, // 1 MON (18 decimals)
  true
)
console.log(`Expected out: ${sim.amountOut}`)
console.log(`Impact: ${sim.priceImpact}%`)
```

***

### computeV4PoolId()

Computes the deterministic 32-byte pool ID from a `V4PoolKey`.

**Parameters**

| Name      | Type        | Description      |
| --------- | ----------- | ---------------- |
| `poolKey` | `V4PoolKey` | Pool key to hash |

**Returns** `Hex`. 32-byte keccak256 pool ID.

```typescript theme={null}
import { computeV4PoolId } from 'rampart-monad'

const poolId = computeV4PoolId({
  currency0: '0x0000000000000000000000000000000000000000',
  currency1: '0x...',
  fee: 3000,
  tickSpacing: 60,
  hooks: '0x0000000000000000000000000000000000000000'
})
console.log(poolId) // 0x...
```

## Contract Addresses

| Contract    | Address                                      |
| ----------- | -------------------------------------------- |
| PoolManager | `0x000000000004444c5dc75cB358380D2e3dE08A90` |